Here's what I'm looking for...I would like to attach some sort of pouch/pocket organizer on the back of the seat for some more storage, off the bottom of the boat so it can stay dry. Without having to get up and open the front storage bay in the front. Something that could be attached via the screws already in the seat. Anybody done this already? Ideas?

The bungee idea looks great! The PA 12 seat has enough exposed frame that it would be very easy to run bungee cord in various patterns. Perfect to hold that rain jacket when threating rain is overhead. No need to crawl upfront to the hatch to retrieve when it has already started raining

I purchased a spiderweb type bungee net from Harbor Freight that is intended for use on motorcycles. I took the screws out of the back of the seat, stretched the bungee across the seat, and reinstalled the screws and back of the seat. Works perfectly for what you're suggesting. Only cost a few bucks.